Just to put this into perspective:
Who do you actually see, commercially, towing doubles? FedEx.. UPS sometimes. But even then, it's rare.
There's a reason for that.
It's CRAZY DANGEROUS if you have any sort of issue. Even moreso if you have 2 different sized tows, ie 30' 5ver and 12' Jeep. Just the dynamics alone in any type of critical stopping or maneuvering situation gives me the heebie jeebies!
Now.. there's a very simple, and much safer way to get around this situation.. 2 infact:
If it's in your budget, a custom HDT. Park the jeep behind the cab, hook up the RV to the back of the HDT, and your down the road.
If it's not in your budget, you have someone else drive the jeep while you tow the 5ver.
There are several YouTube channels that can show you either way. Frankly, if it was in my budget, I'd be into the HDT, just for the pure safety factor.